Composites of NiMoO4@Ni-Co LDH@NiCo2O4 on Ni foam with a rational microscopic morphology for high-performance asymmetric supercapacitors

Abstract

The structural stability and high capacity of material enable a wide range of applications for asymmetric supercapacitors. In this work, we design a simple route to synthesize NiMoO4@Ni-Co LDH@NiCo2O4 composites on Ni foam. The NiMoO4@Ni-Co LDH@NiCo2O4 has a stable nanorod/nanosheet core-shell structure. In addition, the NiMoO4@Ni-Co LDH150@NiCo2O4 exhibits a high specific capacity of 1035 C g−1 and retained 80.6% of the original capacity after 5000 cycles. Moreover, the asymmetric supercapacitor is assembled by activated carbon and NiMoO4@Ni-Co LDH150@NiCo2O4 as two electrodes respectively, which shows a high energy density of 66.8 Wh kg−1 at a power density of 900 W kg−1. In the meantime, the asymmetric supercapacitor achieved a high voltage window of 1.8 V. The stable core-shell structure of NiMoO4@Ni-Co LDH@NiCo2O4 achieved a high energy density, which shows great potential for energy storage.